Abstract 229: Family Caregiver Stress and Patient Symptom Severity in Heart Failure

Abstract

Background: In chronic illness caregiving, greater family caregiver exposure to patient symptoms is predictive of greater caregiver psychological and physiological stress. Although heart failure (HF) carries high symptom burden, this phenomena is not well-studied in HF caregivers. Objective: To test the hypothesis that caregiver perception of patient HF symptoms is associated with elevated caregiver psychological and physiological stress. Methods: This was a secondary analysis of baseline data from 125 HF caregivers in the Caregiver Opportunities for Optimizing Lifestyle (COOL) study. Psychological stress was measured by caregiver report of care-related strain (Oberst Caregiving Burden Scale), depression (Center for Epidemiological Studies Depression), anxiety (State-Trait Anxiety Index), and general stress (Perceived Stress Scale). Physiological stress was quantified by markers of HPA axis dysfunction (elevated cortisol awakening response [CAR]), endothelial dysfunction (increased PAI-1), and inflammation (increased IL-6, hsCRP). HF symptoms were quantified by caregiver assessment of New York Heart Association (NYHA) Class, dichotomized as asymptomatic [Class I] versus symptomatic [Class II-IV]. Generalized linear models were used to test relationships between symptoms and stress (one model per indicator). IL-6, hsCRP, and PAI-1 were natural log transformed, and CAR was dichotomized based on a cutoff for elevated stress response (>75% increase). All models controlled for sociodemographic confounders (age, gender, race, education, caregiving relationship), with biomarker-specific confounders (comorbidity, adiposity, medications) added to physiological stress models. Results: Caregivers were mostly female (n=115, 92.0%), in their mid-fifties (55.4±11.5), African American (n=72, 57.6%), and the patient’s spouse (n=68, 54.4%) or adult child (n=30, 24.0%). One quarter perceived the patient to be asymptomatic (Class I: n=31, 24.8%; II: n=31, 24.8%; III: n=47, 37.6%; IV: n=15, 12.0%). Symptomatic HF was significantly associated with greater caregiver depression, anxiety, and general stress (β=4.0±1.9, p=0.04; β=3.9±1.4, p<0.01; and β=7.7±2.9, p<0.01, respectively), but not greater care-related strain (β=4.7±3.0, p=0.12). Symptomatic HF was also significantly associated with markers of HPA-axis dysfunction (elevated CAR: OR=3.1, 95% CI=1.0-9.7, p=0.05), endothelial dysfunction (PAI-1: β=0.39±0.16, p=0.01), and increased inflammation as measured by hsCRP (β=0.47±0.22, p=0.04), but not IL-6 (β=0.18±0.15, p=0.21). Conclusions: Overall, patient HF symptoms were associated with greater caregiver psychological and physiological stress. To inform timing and mechanisms for much-needed caregiver interventions, research is needed to determine which aspects of HF symptomatology are most stressful for caregivers across the HF trajectory.